| abstract |
Heterocyclic nitrogen-containing compounds of the formula (II) where R1 and R2 represent, as appropriate, an alkyl group with 1 to 15 carbon atoms, in which also one or more CH2 groups can be replaced by a group chosen from the groups -O-, -S-, -CO-, -O-CO-, -O-COO-, -CH = CH-, -CH-halogen and -CHCN- or also by a combination of two suitable groups, provided that two hetero atoms are not directly linked to each other, m represents 0 or 1, Ar represents 1,4-phenilene, 4,4'-bi-phenylyl or 2,6- naphthalene, one or more CH groups being replaced as appropriate by N, Z represents -CO-O-, -O-CO, -CH2O-, -OCH2-, -CH2CH2-, -CH2CHCN-, -CHCNCH2-, -CH = CH or a single bond and A means 1,4 unsubstituted or substituted cyclohexilene by CN in position 1 or 4, provided that in the case where A = 1,4 unsubstituted cyclohexilene, Z means -CHCNCH2- or - CH2CHCN and where in at least one of the residues R1 and R2 at least one group C H2 is replaced by -CHCN-, these compounds being suitable for use as constituents of smectic phases of liquid crystal phases. |